Step 1: Cotton Count.
Cotton count represents the number of 840-yard hanks weighing one pound.
Thus, Cotton Count corresponds to II.
Step 2: Tex System.
Tex is the yarn weight in grams per 1000 meters.
Thus, Tex corresponds to III.
Step 3: Worsted Count.
Worsted count is based on the number of 560-yard hanks per pound.
Thus, Worsted Count corresponds to I.
Step 4: Metric Count.
Metric count is defined as the yarn weight in kilograms per kilometer.
Thus, Metric Count corresponds to IV.
Step 5: Conclusion.
Therefore, the correct match is: A - II, B - III, C - I, D - IV.